Nitrilotriacetato Complexes of Lanthanides - A Thermochemical Study

The heats of formation of mono- and bis-nitrilotriacetato complexes of tervalent lanthanide ions were measured calorimetrically at 20\u27 C in 0.1 M KN03• From the experimental heat data and the formation constants determined by others under similar experimental conditions the entropy changes on coordination were calculated. A support is given for the opinion that, in essentially electrostatic complexes, the complex formation enthalpies and entropies are mutually correlated because of the displacement of solvent molecules in complex formation